Pressure-Induced Metallization and Electrical Phase Diagram for Polycrystalline CaB6 under High Pressure and Low TemperatureSupported by the National Basic Research Program of China under Grant No 2011CB808204, and the National Natural Science Foundation of China under Grant Nos 11374121 and 11404133

• Published in: Chinese physics letters Vol. 33; no. 8
• Main Authors: Yang, Jie, Jiao, Yang, Han, Yong-Hao, Li, Jing
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing 01.08.2016
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/33/8/086201

The electrical properties of polycrystalline CaB6 are revealed by in-situ resistance measurements under high pressure and low temperature. Due to the existence of grain boundaries, polycrystalline CaB6 behaves with semiconducting transport properties, which is different from the semimetallic CaB6 single crystals. The temperature-dependent resistance measurement results show that before the structural phase transition at 12.3 GPa the high pressure first induces the metallization at 6.5 GPa for CaB6. Moreover, the phase diagram for CaB6 is drawn based on the investigated electric conducting properties and at least three different conducting phases are found even at moderate high pressure and low temperature, indicating that the electric nature of CaB6 is very sensitive to the environment.